If you are trying to use Dropbox as a source of images in your collections imports, you are probably frustrated because it doesn’t work. Well I was finally able to get a support guy reveal a little secret that made it work. All you need to do is add “?raw=1” to the URL.
To be exact, when I copied the URL from Dropbox, I got this:
<? https://www.dropbox.com/s/63xu2slzpm4jwq3/image-name.jpg It didn't work. I added "?raw=1" to the end of it: https://www.dropbox.com/s/63xu2slzpm4jwq3/image-name.jpg?raw=1 and it worked :) I hope this helps!